For the past five years, a team of researchers and film experts, led by Lawrence Livermore National Laboratory (LLNL) weapon physicist Greg Spriggs, have been hunting down the footage to scan, reanalyze and declassify the decomposing films.

Spriggs said he and his team are in a race against time to collect and scan the films, before they are lost forever.

"You can smell vinegar when you open the cans, which is one of the byproducts of the decomposition process of these films," Spriggs said. "We know that these films are on the brink of decomposing to the point where they'll become useless. The data that we're collecting now must be preserved in a digital form, because no matter how well you treat the films, no matter how well you preserve or store them, they will decompose. We got to this project just in time to save the data."

The team has located about 6,500 of the films. Around 4,200 have been scanned and some 750 have been declassified by the U.S. government. Now, an initial collection of 64 videos — all showing tests conducted by the LLNL —have been published on the agency’s YouTube channel.

Beyond the historical significance of the films, the LLNL researchers said footage of the nuclear tests can also help post-Cold War-era scientists better understand the impact of nuclear weapons and determine whether the aging U.S. nuclear deterrent — nuclear weapons intended to deter other countries from nuclear attacks — is safe, secure and effective.

By comparing the restored footage to the original data sheets for each test, Spriggs found that some of the published data was incorrect. When the tests were conducted more than a half-century ago, researchers had to rely on "eyeball measurements" of the nuclear test's fireball and shockwave, according to the LLNL researchers, from each frame captured.

"We were finding that some of these answers were off by 20, maybe 30, percent,” Spriggs said. “That's a big number for doing code validation. One of the payoffs of this project is that we're now getting very consistent answers.”

Tests were filmed by multiple cameras at different angles to capture around 2,400 frames per second, the researchers said, and about 1,000 analysts were needed to do the work. Now scientists use computers for analysis, with programs able to take exact measurements from each frame captured.

Spriggs estimates it will take another two years to scan the rest of the films, and longer to complete the analysis and declassification.

He notes the project is so important to him and his colleagues because they don't want nuclear weapons to be used and they passionately believes the key to ensuring they aren't is in making sure the U.S. stockpile continues to be an effective deterrent.

"I think that if we capture the history of this and show what the force of these weapons are and how much devastation they can wreak, then maybe people will be reluctant to use them,” Spriggs added.